US9072602B2 - Transcatheter valve prosthesis having a variable shaped cross-section for preventing paravalvular leakage - Google Patents

Abstract

A transcatheter valve prosthesis includes a self-expanding tubular stent component and a prosthetic valve disposed within and secured to the stent component. The tubular stent component has a proximal portion, a distal portion, and an intermediate portion between the proximal and distal portions. In a compressed delivery configuration, the tubular stent component has a generally circular cross-section along its length. In an expanded deployed configuration, the proximal and distal portions have a generally circular cross-section while the intermediate portion of the stent component has a generally triangular cross-section with three vertexes that are configured to project into three commissural points of a native valve when the valve prosthesis is implanted in situ. The generally triangular transverse cross-section of the valve prosthesis is formed by pulling or extending selected or particular struts of the stent component radially outwards and then applying heat to heat-set the stent component in the deployed configuration.

Description

FIELD OF THE INVENTION

Embodiments hereof relate to transcatheter valve prostheses that prevent paravalvular leakage. More specifically, the present invention relates to a transcatheter valve prosthesis having a variable shaped cross-section along its length to prevent paravalvular leakage.

BACKGROUND OF THE INVENTION

A human heart includes four heart valves that determine the pathway of blood flow through the heart: the mitral valve, the tricuspid valve, the aortic valve, and the pulmonary valve. The mitral and tricuspid valves are atrioventricular valves, which are between the atria and the ventricles, while the aortic and pulmonary valves are semilunar valves, which are in the arteries leaving the heart. Ideally, native leaflets of a heart valve move apart from each other when the valve is in an open position, and meet or “coapt” when the valve is in a closed position. Problems that may develop with valves include stenosis in which a valve does not open properly, and/or insufficiency or regurgitation in which a valve does not close properly. Stenosis and insufficiency may occur concomitantly in the same valve. The effects of valvular dysfunction vary, with regurgitation or backflow typically having relatively severe physiological consequences to the patient.

Recently, flexible endoluminal prosthetic valves supported by stent structures that can be delivered percutaneously using a catheter-based delivery system have been developed for heart and venous valve replacement. These prosthetic valves may include either self-expanding or balloon-expandable stent structures with valve leaflets attached to the interior of the stent structure. The prosthetic valve can be reduced in diameter, by crimping onto a balloon catheter or by being contained within a sheath component of a delivery catheter, and advanced through the venous or arterial vasculature. Once the prosthetic valve is positioned at the treatment site, for instance within an incompetent native valve, the stent structure may be expanded to hold the prosthetic valve firmly in place. One example of a stented prosthetic valve is disclosed in U.S. Pat. No. 5,957,949 to Leonhardt et al. entitled “Percutaneous Placement Valve Stent”, which is incorporated by reference herein in its entirety. Another example of a stented prosthetic valve for a percutaneous pulmonary valve replacement procedure is described in U.S. Patent Application Publication No. 2003/0199971 A1 and U.S. Patent Application Publication No. 2003/0199963 A1, both filed by Tower et al., each of which is incorporated by reference herein in its entirety.

Although transcatheter delivery methods are intended to provide safer and less invasive methods for replacing a defective native heart valve, leakage between the implanted prosthetic valve and the surrounding native tissue is a concern. Preventing leakage at the commissural points of the native valve leaflets is of particular concern as at each commissural point, a gap may exist between the expanded prosthetic valve frame and the wall of the native annulus. More particularly,FIG. 1 illustrates a cross-sectional view of a heart having an aortic valve AV, with arrows indicating the direction of blood flow through of the aortic valve AV from the left ventricle LV into the aorta A.FIG. 2 is a cut-away view illustrating the general anatomy of the aortic valve AV extending between the left ventricle LV into the aorta A. The aortic valve AV includes a first or proximal region including a virtual basal ring or a native valve annulus A_Nand a second or distal region including three native valve leaflets L_N, although only two leaflets are shown in the cutaway view ofFIG. 2. As illustrated, the proximal region or valve annulus A_Nhas a generally circular cross-section C_Cwhile the distal region or area between the native valve leaflets L_Nis not circular but rather has a generally triangular cross-section C_T. The vertexes of the generally triangular cross-section correspond to the commissural points CP of the native valve leaflets L_N.

FIG. 3 is a top-down view of the aortic valve AV with aprosthetic heart valve300 implanted therein.Prosthetic heart valve300 has a circular cross-sectional along an entire length thereof. When expanded within the native valve leaflets L_N, the outer surface ofprosthetic heart valve300 does not provide an exact fit in the area between the native valve leaflets L_N. Gaps302 may form or be present between a perimeter or outer surface ofprosthetic heart valve300 and the surrounding native tissue, particularly at the commissural points CP of the native valve leaflets L_N. As the prosthetic valve assumes responsibility for regulating blood flow through the native valve,gaps302 can make it difficult forprosthetic heart valve300 to form a blood tight seal between the prosthetic valve and the native tissue, causing undesirable paravalvular leakage and/or regurgitation at the implantation site.

Embodiments hereof are related to a transcatheter valve prosthesis having a variable or non-uniform shaped cross-section along its length to prevent paravalvular leakage.

BRIEF SUMMARY OF THE INVENTION

Embodiments hereof relate to a valve prosthesis including a tubular stent component defining a lumen therethrough and having a compressed delivery configuration for transcatheter delivery within a vasculature and a deployed configuration for implantation within a native heart valve. In the delivery configuration, the tubular stent component has a generally circular cross-section along its length. In the deployed configuration, the tubular stent component includes a first portion having a generally circular cross-section and a second portion having a generally triangular cross-section. A prosthetic valve component is disposed within and secured to the stent component.

Embodiments hereof also relate to a transcatheter valve prosthesis including a tubular self-expanding stent component defining a lumen therethrough and having a deployed configuration for implantation within a native heart valve. The tubular stent component has a proximal portion, a distal portion, and an intermediate portion between the proximal and distal portions. The tubular stent component has a variable shaped cross-section when in the deployed configuration in which at least the intermediate portion has a generally triangular cross-section with three vertexes that are configured to project into three commissural points of a native valve when the valve prosthesis is implanted in situ. A prosthetic valve component is disposed within and secured to the stent component, wherein the prosthetic valve component includes three valve leaflets.

BRIEF DESCRIPTION OF DRAWINGS

The foregoing and other features and advantages of the invention will be apparent from the following description of embodiments hereof as illustrated in the accompanying drawings. The accompanying drawings, which are incorporated herein and form a part of the specification, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention. The drawings are not to scale.

FIG. 1 illustrates a sectional view of a heart having an aortic valve AV, with arrows indicating the direction of blood flow through of the aortic valve AV.

FIG. 2 is a cut-away view illustrating the general anatomy of the aortic valve AV.

FIG. 3 is a top-down view of an aortic valve AV with an exemplary prior art prosthetic heart valve implanted therein.

FIG. 4 is a side view of a heart valve prosthesis according to an embodiment hereof, wherein the heart valve prosthesis is depicted in a compressed, delivery configuration.

FIG. 4A is a cross-sectional view taken along line A-A ofFIG. 4.

FIG. 5 is a side view of the heart valve prosthesis ofFIG. 4, wherein the heart valve prosthesis is depicted in an expanded, deployed configuration.

FIG. 5A depicts a cross-sectional view of a support structure of the heart valve prosthesis ofFIG. 4 taken along line A-A ofFIG. 5.

FIG. 5B depicts a cross-sectional view of a support structure of the heart valve prosthesis ofFIG. 4 taken along line B-B ofFIG. 5.

FIG. 5C depicts a cross-sectional view of a support structure of the heart valve prosthesis ofFIG. 4 taken along line C-C ofFIG. 5.

FIGS. 6A-6D illustrate alternate configurations of generally triangular cross-sections of a support structure of the heart valve prosthesis ofFIG. 4 according to embodiments hereof.

FIG. 7 illustrates a heart valve prosthesis which includes a variable cross-sectional shape along its length to prevent paravalvular leakage according to another embodiment hereof.

FIGS. 8 and 9 are side and top views, respectively, of the heart valve prosthesis ofFIG. 7 with the valve leaflets and graft material removed for clarity purposes.

FIG. 8A depicts a portion of a framework of the heart valve prosthesis ofFIG. 8 removed from the remainder of the framework for sake of illustration only.

FIG. 10 is a side view of a heart valve prosthesis according to another embodiment hereof, wherein the heart valve prosthesis is depicted in an expanded, deployed configuration in which the prosthesis has a profile with an enlarged or flared end.

FIG. 11 is a side view of a heart valve prosthesis according to another embodiment hereof, wherein the heart valve prosthesis is depicted in an expanded, deployed configuration in which the prosthesis has an hourglass profile.

FIG. 12 is a side view of a heart valve prosthesis according to another embodiment hereof, wherein the heart valve prosthesis is depicted in an expanded, deployed configuration in which the heart valve prosthesis has a generally straight profile.

DETAILED DESCRIPTION OF THE INVENTION

Specific embodiments of the present invention are now described with reference to the figures, wherein like reference numbers indicate identical or functionally similar elements. The terms “distal” and “proximal” are used in the following description with respect to the heart. “Distal” or “distally” are a position or in a direction away from the heart and “proximal” and “proximally” are a position near or in a direction toward the heart. Regarding “proximal” and “distal” positions referenced herein, a proximal end of a prosthesis is the end closest to the heart by way of blood flow path whereas a distal end of the prosthesis is the end furthest away from the heart during deployment.

The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Although the description of the invention is in the context of treatment of heart valves, the invention may also be used where it is deemed useful in other valved intraluminal sites that are not in the heart. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.

Embodiments hereof relate to a transcatheter valve prosthesis that prevents or minimizes paravalvular leakage by having a cross-sectional shape that varies or is non-uniform along a length of the prosthesis in a deployed or expanded configuration. The valve prosthesis includes a portion having a generally triangular cross-section that conforms to or imitates the shape of the native heart valve, particularly at the location of the commissural points of the native valve leaflets, to substantially prevent gaps between the perimeter of a heart valve prosthesis and the native valve tissue. “Substantially prevents gaps” as utilized herein means that blood flow between the perimeter of a deployed heart valve prosthesis and the native valve tissue is occluded or blocked, or stated another way blood is not permitted to flow there through.

FIG. 4 illustrates a transcatheterheart valve prosthesis400 according to an embodiment hereof.Heart valve prosthesis400 includes anexpandable stent component404 that supports aprosthetic valve component406 within the interior ofstent component404.Stent component404 is a generally tubular support structure that defines alumen405 therethrough.Stent component404 includes aframework401 that defines a plurality of diamond or kite-shapedopenings403. Each diamond-shapedopening403 is defined by four vertexes orvertices409 and four segments or struts411 extending or formed betweenvertexes409. In this embodiment,framework401 has a lattice configuration which is laser cut from a tube and is formed as a unitary structure or component. In embodiments hereof,stent component404 has a shape memory to self-expand or return to an expanded or deployed state shown inFIG. 5 from a compressed or delivery state shown inFIG. 4 and may be made from stainless steel, a pseudo-elastic metal such as a nickel titanium alloy or Nitinol, or a so-called super alloy, which may have a base metal of nickel, cobalt, chromium, or other metal. “Self-expanding” as used herein means that a structure/component has a mechanical memory to return to the expanded or deployed configuration. Mechanical memory may be imparted to the wire or tubular structure that formsstent component404 by thermal treatment to achieve a spring temper in stainless steel, for example, or to set a shape memory in a susceptible metal alloy, such as nitinol, or a polymer, such as any of the polymers disclosed in U.S. Pat. Appl. Pub. No. 2004/0111111 to Lin, which is incorporated by reference herein in its entirety.

Prosthetic valve component406 ofvalve prosthesis400 is capable of blocking flow in one direction to regulate flow there through via threevalve leaflets407 that form a tricuspid replacement valve. More particularly,heart valve prosthesis400 is configured for placement within a native valve having three leaflets such as the aortic, tricuspid, or pulmonary valves.Valve leaflets407 are sutured or otherwise securely and sealingly attached to the interior surface ofstent component404 and/or graft material (not shown inFIG. 4) which encloses orlines stent component404 as would be known to one of ordinary skill in the art of prosthetic tissue valve construction.

Leaflets407 may be made of pericardial material; however, the leaflets may instead be made of another material. Natural tissue for replacement valve leaflets may be obtained from, for example, heart valves, aortic roots, aortic walls, aortic leaflets, pericardial tissue, such as pericardial patches, bypass grafts, blood vessels, intestinal submucosal tissue, umbilical tissue and the like from humans or animals. Synthetic materials suitable for use asleaflets407 include DACRON® polyester commercially available from Invista North America S.A.R.L. of Wilmington, Del., other cloth materials, nylon blends, polymeric materials, and vacuum deposition nitinol fabricated materials. One polymeric material from which the leaflets can be made is an ultra-high molecular weight polyethylene material commercially available under the trade designation DYNEEMA from Royal DSM of the Netherlands. With certain leaflet materials, it may be desirable to coat one or both sides of the leaflet with a material that will prevent or minimize overgrowth. It is further desirable that the leaflet material is durable and not subject to stretching, deforming, or fatigue.

Similarly, a graft material (not shown) for use withvalve prosthesis400 may also be a natural or biological material such as pericardium or another membranous tissue such as intestinal submucosa. Alternatively, the graft material may be a low-porosity woven fabric, such as polyester, Dacron fabric, or PTFE, which creates a one-way fluid passage when attached to the stent component. In one embodiment, the graft material may be a knit or woven polyester, such as a polyester or PTFE knit, which can be utilized when it is desired to provide a medium for tissue ingrowth and the ability for the fabric to stretch to conform to a curved surface. Polyester velour fabrics may alternatively be used, such as when it is desired to provide a medium for tissue ingrowth on one side and a smooth surface on the other side. These and other appropriate cardiovascular fabrics are commercially available from Bard Peripheral Vascular, Inc. of Tempe, Ariz., for example.

Stent component404 may be considered to have three contiguous portions or regions, aproximal portion412, adistal portion408, and an intermediate waist portion ormidsection410 extending between proximal anddistal portions412,408. It will be understood by one of ordinary skill in the art that the length of each portion may vary according to application and is not limited to the proportions shown inFIGS. 4-5. In one embodiment, the length ofmidsection410 is approximately equal to the length of a native leaflet of the native valve, which depends upon the type and size of the native valve and may vary between 5 mm and 20 mm. As previously statedFIG. 4 illustratesheart valve prosthesis400 in a delivery state or configuration, whileFIG. 5 illustratesheart valve prosthesis400 in a deployed state or configuration. In the embodiment depicted inFIGS. 4-5,stent component404 ofvalve prosthesis400 has a cylindrical compressed delivery configuration and an expanded or deployed configuration in which the prosthesis has a profile with an enlarged or flaredproximal end412 that is wider thandistal portion408. Stated another way,proximal portion412 has nominal deployed diameter D₁anddistal portion408 has nominal deployed diameter D₂, which is less than diameter D₁. When configured as a replacement for an aortic valve, widerproximal portion412 functions as an inflow end ofheart valve prosthesis400 and extends into and anchors within the aortic annulus of a patient's left ventricle, while narrowerdistal portion408 functions as an outflow end ofheart valve prosthesis400 and is positioned in the patient's ascending aorta.

In the delivery configuration ofFIG. 4,tubular stent component404 has a generally circular cross-section along an entire length as shown inFIG. 4A. As used herein, “generally” circular includes circular, elliptical, or oval shapes. The uniform circular cross-section oftubular stent component404 in the delivery configuration minimizes the crimped profile ofvalve prosthesis400 during delivery. In the deployed configuration ofFIG. 5,proximal portion412 has a generally circular cross-section as shown inFIG. 5A which is configured to be positioned within an annulus portion of the native valve.Intermediate portion410 has a generally triangular cross-section as shown inFIG. 5B. When positioned in situ,intermediate portion410 abuts against or is disposed within a leaflet portion of the native valve and the generally triangular cross-section conforms to the surrounding or adjacent tissue of the native valve leaflets. In particular, the generally triangular cross-section includes threevertexes414,416,418 and threesegments420 extending between the vertexes.Vertexes414,416,418 are configured to project into or align with the three commissural points of the native valve leaflets.Distal portion408 includesprosthetic valve leaflets407 therein and has a circular cross-section as shown inFIG. 5C. When positioned in situ,distal portion408 is located distal to the native valve leaflets, which are located adjacent tointermediate portion410 as described above. In another embodiment hereof (not shown),distal portion408 may have a generally triangular cross-section and may be configured in situ to abut against or be disposed within the native valve leaflets.

As used herein, “generally” triangular includes: the cross-section ofFIG. 5B in whichsegments420 of the triangle between adjacent vertexes are slightly rounded and bow outwards in a radial direction; the cross-section ofFIG. 6A in whichstraight segments420A of the triangle extend betweenpointed vertexes414A,416A,418A; the cross-section ofFIG. 6B in whichstraight segments420B of the triangle extend betweenrounded vertexes414B,416B,418B; the cross-section ofFIG. 6C in which curved or radially bowedsegments420C of the triangle extend between elongatedcurved vertexes414C,416C,418C; and the cross-section ofFIG. 6D in which curved or radially bowedsegments420D of the triangle extend between elongated pointedvertexes414D,416D,418D. The generally triangular cross-sections of FIGS.5B and6A-6D are generally shown as equilateral triangles but in other embodiments hereof the triangular cross-section may form an isosceles or scalene triangle with right, acute or obtuse angles depending on the anatomy and level of disease of the native heart valve. In any case, the generally triangular cross-section includes three vertexes and three segments therebetween which are configured to be a shape and size that can provide a sealing function forvalve prosthesis400 when the prosthesis is deployed at a native valve target site.

A generally triangular cross-section, as taken or made transverse to a longitudinal axis of a valve prosthesis, is formed by extending particular or selected portions of the stent component framework radially outwards with respect to the rest of framework. A method of forming a generally triangular cross-section on a valve prosthesis is described in more detail with respect to the embodiment depicted inFIGS. 7,8, and9. More particularly,FIGS. 7,8, and9 illustrate another embodiment hereof in which aheart valve prosthesis700 is configured for placement in an aortic valve and includes a variable or non-uniform cross-sectional shape along its length to prevent paravalvular leakage. As shown in the side view ofFIG. 7,heart valve prosthesis700 includes a self-expanding tubular stent component orsupport frame704,graft material730 coupled tostent component704 via a plurality ofstitches744, andvalve leaflets707 located towards adistal outflow end742 ofstent component704. In one embodiment,heart valve prosthesis700 may be an Engager™ Aortic Valve Prosthesis from Medtronic CardioVascular, Inc., described in U.S. Patent Application Pub. No. 2010/0262231 to Tuval et al. which is herein incorporated by reference in its entirety, that has been adapted for use as described herein to have a generally triangular cross-section on at least an intermediate portion thereof.

FIGS. 8 and 9 illustrate perspective and top views, respectively, ofstent component704, withvalve leaflets707 andgraft material730 ofheart valve prosthesis700 omitted for clarity.Stent component704 includes aframework701 that defines a plurality of diamond-shapedopenings703. Each diamond-shapedopening703 is defined by four vertexes orvertices709 and four segments or struts711 extending or formed betweenvertexes709. In this embodiment,framework701 may be formed by bending or manipulating one or more wires, strands or filaments into the configuration shown inFIG. 8.Stent component704 includescommissural posts734 provided atdistal end742 ofstent component704.Heart valve prosthesis700 is implanted in situ such that, after being expanded to its deployed configuration, thecommissural posts734 are oriented in the native valve in a position corresponding to the commissural points of the native valve leaflets.Stent component704 further includes three self-expandingsupport arms738, which are attached to or formed integrally withstent component704 towards itsdistal end742, and are radially pivotable with respect to an outer surface ofstent component704.Support arms738, which are visible on fluoroscopic imaging during implantation, assist in accurately positioning or orientingheart valve prosthesis700 in situ as described in more detail in U.S. Patent Application Pub. No. 2010/0262231 to Tuval et al., previously incorporated by reference. Whenheart valve prosthesis700 is implanted in situ, supportarms738 rest on body tissue adjacent to the outflow end of the native valve, thereby bracing or anchoringheart valve prosthesis700 within the native valve.Stent component704 may also include three fixation hooks732 andbarbs736 at aproximal inflow end740 ofstent component704 for coupling the stent component to a delivery system (not shown).

Similar to other embodiments described herein,stent component704 defines three contiguous portions or regions including aproximal inflow portion712, adistal outflow portion708, and an intermediate waist portion ormidsection710 extending between proximal anddistal portions712,708. In a compressed or delivery configuration (not shown),stent component704 has a generally circular cross-section along its length as described above with respect tostent component404 andFIG. 4A. In the expanded or deployed configuration ofprosthesis700 depicted inFIG. 8, proximal anddistal portions712,708 have a generally circular cross-section whileintermediate portion710 has a generally triangular cross-section having threevertexes714,716,718.

With reference toFIG. 9,vertexes714,716,718 of the generally triangular cross-section ofintermediate portion710 ofvalve prosthesis700 are formed by pulling, pinching or otherwise extending three portions orregions750A,750B,750C ofstent component704 radially outwards and heat setting the stent component. In an embodiment hereof, the manufacture ofintermediate portion710 may be performed with two heat setting steps. More particularly, a generally cylindrical stent is formed with a first heat setting step, three portions orregions750A,750B,750C ofstent component704 are pulled, pinched or otherwise extended radially outwards to formvertexes714,716,718, and an additional, second heat setting step is utilized to set or formintermediate portion710 in a generally triangular cross-section. In another embodiment hereof, the manufacture ofintermediate portion710 may be performed with one heat setting step. More particularly, a mandrel having an outer surface corresponding to the desired final shape or configuration of the valve prosthesis is inserted into a generally cylindrical stent, which expands or molds into the mandrel shape, and then the mandrel and stent thereon are heat set in a single heating step.

Regardless of whether one or more heat setting steps are utilized in the method of manufacture, the manufacture ofintermediate portion710 includes pulling or extendingportions750A,750B,750C offramework701 out of or away from a cylindrical plane formed bytubular stent component704.Selected region750A, which is darkened or bold inFIG. 8 andFIG. 9 for illustrative purposes only, is shown inFIG. 8A removed from the remainder of theframework701 for illustrative purposes only. Selected portions orregions750A,750B,750C offramework701 ofstent component704 are proximal to and longitudinally aligned withcommissural posts734, and are configured to be oriented in situ in a position corresponding to or adjacent to the commissural points of the native valve leaflets. Accordingly,vertexes714,716,718 configured to project into or align with the three commissural points of the native valve leaflets. Selected portions orregions750A,750B,750C offramework701 include avertex709A offramework701 and fourstruts711A that extend or radiate from the selected vertex409A in an “X” configuration. Whenvertex709A and struts711A are pulled or otherwise extended outwards, additional vertexes and/or struts offramework701 that are near or adjacent tovertex709A and struts711A may also be slightly pulled or extended radially outwards butvertex709A offramework701 forms one ofvertexes714,716,718 of the generally triangular cross-section. For example, in the embodiment ofFIG. 8,vertexes709B and struts711B which are adjacent to struts711A may be slightly pulled or extended radially outwards whenvertex709A is pulled or extended radially outwards because in this embodiment vertexes709B are not coupled to other adjacent vertexes offramework701.

Delivery ofheart valve prosthesis700, or a heart valve prosthesis according to any embodiment hereof, may be accomplished with a delivery catheter (not shown). During delivery, the heart valve prosthesis remains in its compressed delivery configuration until it reaches a target diseased native heart valve, at which time the heart valve prosthesis can be released from the delivery catheter in situ to self-expand to the deployed configuration. The delivery catheter is then removed and the heart valve prosthesis remains deployed within the native target heart valve. In another embodiment hereof, a heart valve prosthesis according to any embodiment described herein may be balloon-expandable and a balloon catheter may be utilized for expanding the heart valve prosthesis to the deployed configuration. The balloon catheter may include a non-cylindrical balloon at its distal end for expanding the heart valve prosthesis. In one embodiment, the non-cylindrical balloon includes at least two contiguous portions or regions, a first portion having a generally triangular cross-section and a second portion having a generally circular cross-section, which correspond to and align with the portions of the heart valve prosthesis having generally triangular and circular cross-sections, respectively, for expanding the prosthesis to its final deployed configuration.

Fluoroscopy can be used to assist in orientation of the heart valve prosthesis in situ. Precise rotational positioning/orientation ofheart valve prosthesis700 allows a clinician to positionvertexes714,716,718 of the generally triangular cross-section into the native commissure points of the native valve leaflets. In an embodiment hereof, the heart valve prosthesis and/or the delivery system may include one or more features to identify the orientation of the heart valve prosthesis on fluoroscopic image. In one embodiment hereof, delivery of a heart valve prosthesis according to any embodiment hereof may be accomplished via a percutaneous transfemoral approach and the delivery system may include a rotational identifier that identifies the rotational orientation of the heart valve prosthesis in situ, as described in more detail in U.S. Patent Application Pub. No. 2012/0158129 to Duffy et al., herein incorporated by reference in its entirety. In another embodiment hereof, delivery of a heart valve prosthesis according to any embodiment hereof may be accomplished via a transapical approach directly through the apex of the heart via a thoracotomy or by other close range transcatheter delivery methods. A transapical approach requires a relatively shorter length of catheter, as compared to a percutaneous transfemoral approach, and therefore may allowheart valve prosthesis700 to be more accurately oriented in the native valve, as described in more detail in U.S. Patent Application Pub. No. 2010/0262231 to Tuval et al. previously incorporated by reference. Other techniques for assisting in rotational positioning/orientation ofheart valve prosthesis700 include pre-implant planning via computed tomography (CT) or other imaging modalities, image fusion technologies for transcatheter aortic-valve implantation (TAVI), and/or utilization of electromagnetic sensors or accelerometers.

It is would be understood by one of ordinary skill in the art upon reading the entire disclosure hereof that any number of alternate heart valve prostheses may be adapted for use in embodiments hereof to include a generally triangular cross-section to prevent paravalvular leakage and the location of the generally triangular cross-section along the length of heart valve prosthesis may vary according to the configuration thereof. For example,FIG. 10 illustrates aheart valve prosthesis1000 including a self-expanding tubular stent component orsupport frame1004 and aprosthetic valve component1006 secured withinstent component1004.Stent component1004 includes aframework1001 that defines a plurality of diamond or kite-shapedopenings1003. Each diamond-shapedopening1003 is defined by four vertexes orvertices1009 and four segments or struts1011 extending or formed betweenvertexes1009. In this embodiment,framework1001 is formed from a plurality of sinusoidal rings that are coupled together at the bends or apexes of the sinusoid to form diamond-shapedopenings1003. Similar to the embodiments described above,stent component1004 includes aproximal inflow portion1012, adistal outflow portion1008, and an intermediate waist portion ormidsection1010.Stent component1004 ofvalve prosthesis1000 has a cylindrical compressed or delivery configuration (not shown but as described above with respect tostent component404 andFIG. 4A) and a deployed configuration (shown inFIG. 10) in which the prosthesis has a profile with an enlarged or flareddistal portion1008 that is wider thanproximal portion1012.Distal portion1008 has nominal deployed diameter D₁andproximal portion1012 has nominal deployed diameter D₂, which is less than diameter D₁. When configured as a replacement for an aortic valve,proximal portion1012 functions as an inflow end ofheart valve prosthesis1000 and extends into and is positioned within the aortic annulus of a patient's left ventricle, whiledistal portion1008 functions as an outflow end ofheart valve prosthesis1000 and is positioned in the patient's ascending aorta.

In the expanded or deployed configuration ofFIG. 10, proximal anddistal portions1012,1008 have generally circular cross-sections whileintermediate portion1010 has a generally triangular cross-section. The generally triangular cross-section ofintermediate portion1010, which in this embodiment also includesprosthetic valve component1006 secured therein, is configured to be positioned in situ such that it abuts against or is adjacent to the commissural points of the native valve leaflets.Proximal portion1012 having a generally circular cross-section is configured to be positioned within an annulus portion of the native valve, anddistal portion1008 having a generally circular cross-section is located distal to the native valve leaflets. In one embodiment,heart valve prosthesis1000 may be a CoreValve™ valve prosthesis from Medtronic CardioVascular, Inc., described in U.S. Patent Application Pub. No. 2011/0172765 to Nguyen et al. which is herein incorporated by reference in its entirety, that has been adapted for use as described herein to have a generally triangular cross-section on at least an intermediate portion thereof.

FIGS. 11 and 12 illustrate alternative configurations of heart valve prostheses having a variable cross-sectional shape along their lengths to prevent paravalvular leakage. As alternatives to the deployed configurations described above, the stent component/valve support frame may have a deployed configuration in which the prosthesis has an hourglass profile, a deployed configuration in which the prosthesis has a generally straight profile, or other stent configuration or shape known in the art for valve replacement. The stent component may be designed with a number of different configurations and sizes to meet the different requirements of the location in which it may be implanted.

For example,FIG. 11 illustrates aheart valve prosthesis1100 having a deployed configuration in which the prosthesis has an hourglass profile.Heart valve prosthesis1100 includes a self-expanding tubular stent component orsupport frame1104 and aprosthetic valve component1106 secured withinstent component1104.Stent component1104 has a cylindrical compressed delivery configuration (not shown but as described above with respect tostent component404 andFIG. 4A) and a deployed configuration (shown inFIG. 11) in which proximal anddistal portions1112,1108 have a generally circular cross-section while anintermediate portion1110 has a generally triangular cross-section which is configured to be positioned in situ such that it abuts against or is adjacent to the commissural points of the native valve leaflets. In the deployed configuration ofFIG. 11,distal portion1108 has approximately the same nominal deployed diameter as proximal portion1112, withintermediate portion1110 being contracted or narrowed relative to distal andproximal portions1108,1112. Thus, the deployed width ofintermediate portion1110 having a generally triangular cross-section is less than the deployed diameter of proximal anddistal portions1112,1108 having generally circular cross-sections that are approximately equal.

FIG. 12 illustrates aheart valve prosthesis1200 having a deployed configuration in which the prosthesis has a generally straight profile.Heart valve prosthesis1200 is similar toheart valve prosthesis1100 described herein except that the intermediate portion ofprosthesis1200 is not contracted or narrowed relative to the distal and proximal portions thereof. More particularly, similar to embodiments described above,heart valve prosthesis1200 includes a self-expanding tubular stent component orsupport frame1204 and aprosthetic valve component1206 secured withinstent component1204.Stent component1204 has a cylindrical compressed or delivery configuration (not shown but as described above with respect tostent component404 andFIG. 4A) and a deployed configuration (shown inFIG. 12) in which proximal anddistal portions1212,1208 have a generally circular cross-section while anintermediate portion1210 has a generally triangular cross-section which is configured to be positioned in situ such that it abuts against or is adjacent to the commissural points of the native valve leaflets. In the deployed configuration ofFIG. 12,distal portion1208 has approximately the same nominal deployed diameter asproximal portion1212. Further, the deployed width ofintermediate portion1210 having a generally triangular cross-section is approximately equal to the deployed diameters of proximal anddistal portions1212,1208 having generally circular cross-sections.

While various embodiments according to the present invention have been described above, it should be understood that they have been presented by way of illustration and example only, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the appended claims and their equivalents. It will also be understood that each feature of each embodiment discussed herein, and of each reference cited herein, can be used in combination with the features of any other embodiment. All patents and publications discussed herein are incorporated by reference herein in their entirety.

Claims (18)

What is claimed is:

1. A transcatheter valve prosthesis comprising: a tubular stent component having a framework defining a lumen therethrough and having a compressed delivery configuration for transcatheter delivery within a vasculature and a deployed configuration for implantation within a native heart valve, wherein the framework has a generally circular cross-section along its length when in the delivery configuration and wherein the framework includes a first portion having a generally circular cross-section, a second portion having a generally triangular cross-section, and a third portion having a generally circular cross-section, the second portion being positioned between the first and third portions; and a prosthetic valve component disposed within and secured to the framework.

2. The transcatheter valve prosthesis ofclaim 1, wherein the framework of the generally triangular cross section includes three vertexes that are configured to project into three commissural points of a native valve when the valve prosthesis is implanted in situ.

3. The transcatheter valve prosthesis ofclaim 2, wherein the framework of the circular cross-section is configured to be positioned within an annulus portion of the native valve when the valve prosthesis is implanted in situ.

4. The transcatheter valve prosthesis ofclaim 1, wherein the stent component is self-expanding.

5. The transcatheter valve prosthesis ofclaim 1, wherein the prosthetic valve component includes three valve leaflets.

6. The transcatheter valve prosthesis ofclaim 1, wherein the prosthetic valve component is disposed within the framework of the third portion of the stent component.

7. The transcatheter valve prosthesis ofclaim 1, wherein a deployed diameter of the first portion is greater than a deployed diameter of the third portion.

8. The transcatheter valve prosthesis ofclaim 1, wherein a deployed diameter of the first portion is approximately the same as a deployed diameter of the third portion.

9. The transcatheter valve prosthesis ofclaim 8, wherein the second portion has a deployed width that is less than the deployed diameters of the first and third portions.

10. The transcatheter valve prosthesis ofclaim 8, wherein the second portion has a deployed width that is approximately the same as the deployed diameters of the first and third portions.

11. The transcatheter valve prosthesis ofclaim 1, further comprising: commissural posts coupled to or extending from a distal end of the framework, wherein the framework of the generally triangular cross-section includes three vertexes that are proximal to and longitudinally aligned with the commissural posts.

12. The transcatheter valve prosthesis ofclaim 1, further comprising:

at least one self-expanding support arm coupled to a distal end of the stent component, wherein the at least one support arm is operable to pivot radially with respect to the stent component.

13. The transcatheter valve prosthesis ofclaim 1, wherein the prosthetic valve component is disposed within the framework of the second portion of the stent component.

14. A transcatheter valve prosthesis comprising: a tubular self-expanding stent component having a framework defining a lumen therethrough and having a deployed configuration for implantation within a native heart valve, the framework having a proximal portion, a distal portion, and an intermediate portion between the proximal and distal portions, wherein the framework has a variable shaped cross-section when in the deployed configuration in which at least the intermediate portion has a generally triangular cross-section with three vertexes that are configured to project into three commissural points of a native valve when the valve prosthesis is implanted in situ and wherein the proximal and distal portions have a generally circular cross-section when in the deployed configuration; and a prosthetic valve component disposed within and secured to the stent component, wherein the prosthetic valve component includes three valve leaflets.

15. The transcatheter valve prosthesis ofclaim 14, wherein the proximal portion is configured to be positioned within an annulus portion of the native valve when the valve prosthesis is implanted in situ.

16. The transcatheter valve prosthesis ofclaim 14, wherein a deployed diameter of the proximal portion is greater than a deployed diameter of the distal portion.

17. The transcatheter valve prosthesis ofclaim 14, wherein a deployed diameter of the distal portion is greater than a deployed diameter of the proximal portion.

18. The transcatheter valve prosthesis ofclaim 14, wherein the prosthetic valve component is disposed within the framework of the intermediate portion of the stent component.

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